In a fast reactor, an effort for reducing a leakage amount of coolant from a sealing part has been conventionally exerted. The below Patent Document 1 shows an example of a conventional fast reactor, which is shown in FIG. 15.
As shown in FIG. 15, the fast reactor 1 described in Patent Document 1 includes a core 2 formed of a nuclear fuel assembly. The core 2 has a substantially cylindrical shape as a whole. An outer circumference of the core 2 is surrounded by a core barrel 3. A reflector 4 surrounding the core barrel 3 is located outside the core barrel 3. Outside the reflector 4, there is disposed a bulkhead 6 that surrounds the reflector 4 and constitutes an inner wall of a flow path through which a primary coolant 21 (coolant) flows. A reactor vessel 7 constituting an outer wall of the flow path of the primary coolant 21 is located outside the bulkhead 6, with a predetermined clearance therebetween. A neutron shield 8 is disposed in the flow path of the primary coolant 21 such that the neutron shield 8 surrounds the core 2. The core 2, the core barrel 3, the bulkhead 6 and the neutron shield 8 are respectively supported by a core support 13 from below.
In FIG. 15, after the primary coolant 21 is pressurized by an electromagnetic pump 14, the primary coolant 21 passes through the neutron shield 8 and the core supports 13 and then reaches the core 2, whereby the cored 2 is cooled. The primary coolant 21 heated by the core 2 while passing therethrough is sent to an intermediate heat exchanger 15. In the intermediate heat exchanger 15, the heat is exchanged between the primary coolant 21 and a secondary coolant 31. In order to facilitate a maintenance operation, the intermediate heat exchanger 15 is configured to be drawn from the reactor vessel 7. In this case, a seal bellows attached to the intermediate heat exchanger is seated on a bellows seat fixed on the bulkhead 6. The seal bellows is compressed by a weight of the intermediate heat exchanger 15. Thus, the pressurized primary coolant 21 from an outlet of the electromagnetic pump 14 can be sealed against the heated primary coolant 21 inside the bulkhead 6.
Patent Document 1: JP5-119175A